In
addition to periodic tunings, the action of the pianos also needs
to be taken care of. The action of the piano is the intricate
system of levers, springs, hammers, pins, screws and keys that
make possible for you to press a key and get the hammer to hit
a string producing the sound.

The
precision in which every piece must be calibrated to keep it functioning
is very important for the pianist to
be able to control the sound of his instrument from the
loudest scale to the sweetest chord.

Every
single part of the action is also made of wood, felt, leather
and metal, thus being equally affected by humidity and temperature
changes. They are also affected by many other things, such as
moving the piano or just material weariness because of the use.

Every once in a while the action needs to be regulated
to cope with these changes and let the pianist control the instrument
at its best.

On
the other hand, the piano also needs to be voiced every once in
a while: Also because of material weariness, when the felt on
the hammers gets either compacted or deformed it will
change the tone of the note that is played. Commonly,
that change is uneven amongst the hammers of the same piano, so
a periodical work of voicing is needed for that
to be fixed.